Subrack for receiving plug-in units with code pins

ABSTRACT

A subrack ( 1 ) includes a plurality of plug-in units ( 50 ), a pair of parallel sidewalls ( 10, 20 ), a bottom wall ( 24 ) and a top wall ( 30 ). Each plug-in unit engages a combination of code pins ( 60 ). Each of the bottom wall and top wall includes a first plate ( 35 ) and a second plate ( 31 ) engaged with the first plate. The first plate defines a plurality spaced slide channels ( 351 ) for slidably receiving the plug-in units therein respectively, and forms a plurality of L-shaped flakes ( 40 ) corresponding to the combination of code pins in front of each slide channel. The height, length and deviation to slide channel of the flakes vary with different combinations of code pins on the mounting panel, in order to match the combinations of code pins and enable the plug-in units be inserted into the subrack for preventing from mis-inserting operation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to component mounting apparatuses, and particularly to a subrack having code pins with simplified configurations for convenient use to mount plug-in units therein.

2. Description of the Related Art

Subracks for receiving plug-in units therein have been known in the electronics industry for a long time. A typical subrack comprises two sidewalls each having four corners, and four module rails fixed between the sidewalls, the module rails conventionally being screwed to the corresponding corners of the sidewalls. Bottom, top and back walls are attached to the subrack, and cooperate with the sidewalls to define a receiving space therebetween and an open side. The plug-in units can be inserted into and removed from the receiving space via the open side. The plug-in units typically comprise mounting panels engaging with two front module rails to thereby hold the plug-in units in place. For a thorough understanding of this kind of subrack, refer to the IEEE (International Electrical and Electronics Engineers) Standard 1101.10 established in 1996.

Various coding devices are used in subracks to enable plug-in units be correctly mounted to corresponding slide channels. Typically combinations of code pins are often used in subrack. U.S. Pat. No. 5,019,947 discloses a coding device for plug-in unit in subracks. The disclosed coding device comprises a subrack, a circuit board 6 and a plug connection connector 5. The subrack engages a plurality of coding elements 3 and a plurality of guide rails 2. The coding elements 3 defines two slots 4 therein. The plug connection connectors 5 respectively forms two webs 7, 8 corresponding to the slots 4 of the coding elements 3. The webs 7, 8 corresponding to the coding elements 3 so as to provide that coding occurs as soon as the individual coding elements engaged on the subrack complicate the manufacturing process of the subrack. In addition, for production of these rather elaborate components, complicated tools are required and manufacturing of the additional coding elements is quite expensive.

Thus, a new subrack for plug-in units with code pins which overcomes the above-mentioned problems is desired.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a subrack for a plurality of plug-in units, the subrack having a plurality of code pins with simplified configurations.

Another object of the present invention is to provide a subrack easily assembled and having a plurality of code pins with simplified configurations for convenient use.

To achieve the above-mentioned objects, a subrack in accordance with a preferred embodiment of the present invention comprises a plurality of plug-in units, a pair of parallel sidewalls, a bottom wall and a top wall. Each plug-in unit engages a combination of code pins. Each of the bottom wall and top walls includes a first plate and a second plate engaged with the first plate. The first plate define a plurality of spaced slide channels for slidably receiving the plug-in units therein respectively, and forms a plurality of L-shaped flakes corresponding to respective combination of code pins in front of each slide channel. The height, length and deviation to slide channel of the flakes vary with different combinations of code pins on the mounting panel, in order to match the combinations of code pins and enable the plug-in units be inserted into the subrack for preventing from mis-inserting operation.

Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of the preferred embodiment of the present invention with the attached drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric assembled view of a subrack in accordance with the preferred embodiment of the present invention, together with a plug-in unit received therein;

FIG. 2 is an enlarged, isometric view of a part of a bottom wall of the subrack of FIG. 1;

FIG. 3 is similar to FIG. 2, but showing the bottom wall inverted;

FIG. 4 is an enlarged, isometric view of a first combination of code pins;

FIG. 5 is an enlarged, isometric view of a second combination of code pins;

FIG. 6 is an enlarged, isometric view of a third combination of code pins;

FIG. 7 is an enlarged, isometric view of a fourth combination of code pins;

FIG. 8 is a cross-sectional view of the bottom wall of FIG. 2, and showing the plug-in unit engaged therewith;

FIG. 9A is a schematic view of the a first flake engaging with the corresponding combination of code pins therewith;

FIG. 9B is a schematic view of the a second flake engaging with the corresponding combination of code pins therewith;

FIG. 9C is a schematic view of the a third flake engaging with the corresponding combination of code pins therewith; and

FIG. 9D is a schematic view of the a fourth flake engaging with the corresponding combination of code pins therewith.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1 to FIG. 3, a subrack 1 with code pins of the present invention is for receiving a plurality of spaced plug-in units 50 therein. For the sake of simplicity, only one plug-in unit 50 is shown and described hereafter. The subrack 1 of the preferred embodiment has two levels for plug-in units 50. It should be appreciated that the subrack 1 may alternatively be configured to have only one level, or three or more levels. For the sake of describing the preferred embodiment simply, only the upper of the two levels is described hereafter. The subrack 1 comprises two parallel sidewalls 10, and opposite top and bottom walls 24, 30 fixed between the sidewalls 10. The sidewalls 10 and top and bottom walls 24, 30 cooperatively define a space therebetween for receiving the plug-in units 50.

Referring also to FIG. 4, the plug-in unit 50 comprises a printed circuit board (PCB) 51, and a mounting panel 52 attached to a front end of the PCB 51. A pair of handles 56 is attached to top and bottom ends of the mounting panel 52 respectively. Each handle 56 is known in the art as an “injector/extractor handle,” and is used for inserting or extracting the plug-in unit 50 into or from the subrack 1. The handle 56 at a top end of the mounting panel 52 comprises a pair of upwardly-extending claws 57 at a top side thereof. The handle 56 at a bottom end of the mounting panel 52 comprises a pair of downwardly-extending claws 57 at a bottom side thereof. For the sake of simplicity, only the latter of the handles 56 is described hereafter. An alignment pin 54 extends inwardly from an inside of each end of the mounting panel 52. A screw 55 is movably retained in the mounting panel 52 adjacent each alignment pin 54. A screw head 550 located at an outside of the mounting panel 52. Prior to attachment of the plug-in unit 50 in the subrack 1, the screw 55 can be freely moved forward and rearward in the hole. The mounting panel 52 defines three square openings 61 at the bottom side therein, the side length of each opening 61 is denoted “a”. In each opening 61, a plug-in code pin 60 is retained. The length of each code pin 60 is the same with that of each opening, and also denoted “a”, the width of each code pin 60 is denoted “a/2”. The permutation of a code pin 60 in an opening 61 is four, that is upright-left, upright, transverse-up and transverse-down. Thus, the permutation of three code pins 60 is 64 (i.e., 4*4*4).

The top and bottom walls 24, 30 are made from corrosion-protected sheet steel, and are identical in the preferred embodiment. For the sake of simplicity, FIGS. 2 through 3 illustrate only the bottom wall 30. The bottom wall 30 comprises first and second plates 35, 31, which have a same thickness and are attached together by fastening devices such as rivets 33. Alternatively, other fastening means such as soldering can be used for connecting the first and second plates 35, 31 together. To prevent accumulation of static electricity, a plurality of conductive gaskets 32 is attached between the first and second plates 35, 31.

The first plate 35 comprises a main portion 350, and a recessed edge portion 355. A plurality of parallel, evenly spaced slide channels 351 is defined in the main portion 350, for slidingly receiving respective PCBs 51 therein. Preferably, the slide channels 351 are formed by a stamping process. A pair of spaced, divergent protrusions 352 is formed on the main portion 350 in front of each slide channel 351. The protrusions 352 cooperatively form a V-shaped entrance for guiding a corresponding PCB 51 into the slide channel 351. An alignment hole 353 is defined in the main portion 350 adjacent each pair of protrusions 352, corresponding to the alignment pin 54 of a respective plug-in unit 5O. A pair of side flanges 359 depends from opposite ends of the main portion 350 respectively. The side flanges 359 each define a screw hole (not labeled) and a hooking structure (not labeled), for connection of the first plate 35 to the sidewalls 10. Alternatively, other suitable joining means may instead be provided on the side flanges 359 for connection of the first plate 35 to the sidewalls 10.

The recessed edge portion 355 sequentially comprises first, second and third bent plates 355 a, 355 b, 355 c integrally joined together at respective perpendicularly bent junctions therebetween. A row of spaced through apertures 356 is defined in the second bent plate 355 b. A plurality of L-shaped flakes 40 are formed along the first plate 355 a corresponding to the combination of three code pins 61 on the mounting panel 52. Preferably, the flakes 40 are formed by a stamping process. Every two flakes 40 are differential in height, width and deviation to the corresponding slide channel 351, varying with different mounting panel 52 with different combination of code pins 60.

Referring from FIG. 4, to FIG. 9D, in order to reduce manufacturing processes of the subrack 1 and coding a certain number of plug-in units 50, the first plate 355 a of the subrack 1 forms the flakes 40 with simplified configuration. For the sake of simplicity, only the flakes 41, 42, 43, 44 are illustrated hereafter. The flake 41 comprises a vertical portion 41 a and a horizontal portion 41 b. The height of the flake 41 is denoted d1, the length is denoted e1 and the deviation to the slide channel 351 is denoted c1. The flake 42 comprises a vertical portion 42 a and a horizontal portion 42 b. The height of the flake 42 is denoted d2, the length is denoted e2 and the deviation to the slide channel 351 is denoted c2. The flake 43 comprises a vertical portion 43 a and a horizontal portion 43 b. The height of the flake 43 is denoted d3, the length is denoted e3 and the deviation to the slide channel 351 is denoted c3. The flake 44 comprises a vertical portion 44 a and a horizontal portion 44 b. The height of the flake 44 is denoted d4, the length is denoted e4 and the deviation to the slide channel 351 is denoted c4.

Referring from FIG. 4, to FIG. 7 and FIG. 9A to FIG. 9D, four flakes 40 and its corresponding code pins 60 are illustrated. In FIG. 4 and FIG. 9A, a code pin combination 60 a, 60 b, 60 c is disclosed, each code pin 60 a or 60 b or 60 c is engaged in transverse-up position. The corresponding flake 41 is configured as following: the height d1 is less than a/2, the length e1 is longer than 3 a and the deviation c1 to the slide channel 351 is greater than 3 a/2, in order to ensure that the combination of code pins 60 a, 60 b, 60 c can avoid being blocked by the flake 41 and enable the plug-in unit 50 be inserted into the subrack 1.

In FIG. 5 and FIG. 9B, a code pin combination 60 d, 60 e, 60 f is disclosed, each code pin 60 d or 60 e or 60 f is engaged in transverse-down position. The corresponding flake 42 is configured as following: the height d2 is more than a/2, the length e2 is longer than 3 a and the deviation c2 to the slide channel 351 is greater than 3 a/2, in order to ensure that the combination of code pins 60 d, 60 e, 60 f can avoid being blocked by the flake 42 and enable the plug-in unit 50 be inserted into the subrack 1.

In FIG. 6 and FIG. 9C, a code pin combination 60 g, 60 h, 60 i is disclosed, each code pin 60 g is engaged in upright-left position and code pins 60 h or 60 i is engaged in transverse-down position. The corresponding flake 43 is configured as following: the height d3 is more than a/2, the length e3 is greater than 2 a and less than 5 a/2, the deviation c3 to the slide channel 351 is greater than a/2 and less than a, in order to ensure that the combination of code pins 60 g, 60 h, 60 i can avoid being blocked by the flake 43 and enable the plug-in unit 50 be inserted into the subrack 1.

In FIG. 7 and FIG. 9D, a code pin combination 60 j, 60 k, 60 l is disclosed, each code pin 60 j is engaged in upright-left position and code pins 60 k or 60 l is engaged in transverse-down position. The corresponding flake 44 is configured as following: the height d4 is more than a/2, the length e4 is greater than 2 a and less than 5 a/2, the deviation c4 to the slide channel 351 is greater than a/2 and less than a, in order to ensure that the combination of code pins 60 j, 60 k, 60 l can avoid being blocked by the flake 44 and enable the plug-in unit 50 be inserted into the subrack 1.

Referring to FIG. 2 and FIG. 3 again, the second plate 31 comprise a vertical portion 315, and first and second horizontal portions 316, 310 extending from bottom and top sides of the vertical portions 316, 310 extending from bottom and top sides of the vertical portion 315 in respective opposite directions. A row of screw apertures 314 is defined in the vertical portion 315, corresponding to the row of through apertures 356 of the first plate 35. A plurality of pairs of rectangular openings 318 is defined in a front part of the first horizontal portion 316. The pair of rectangular openings 318 can engagingly receive the claw 57 of the handle 56 respectively. A plurality of extensions 311 is formed at a rear side of the second horizontal portion 310, for aligning with the alignment holes 353 and creating corresponding spaces for receiving the gaskets 32. Rivets 33 are extended through the river holes (not labeled), thereby securely joining the first and second plates 35, 31 together.

Each gasket 32 is adhered to the extension 311. Other suitable attachment means such as screw jointing can alternatively be adopted.

In assembly of the plug-in unit 50 into the subrack 1. For the sake of simplicity, only the bottom wall 30 and the corresponding handle 56 of the plug-in unit 50 are shown and described hereafter. The plug-in unit 50 is positioned adjacent a corresponding pair of protrusions 352. The plug-in unit 50 is pushed inwardly to slide through the entrance of the protrusions 352 and into the corresponding slide channel 351. When the PCB 51 almost reaches a connector (not shown) located at a rear of the subrack 1, the alignment pin 54 extends into the alignment hole 353 to guide the PCB 51 to accurately engage with the connector. If the combination of code pins on the mounting panel 52 unmatched with the flake 40 on the first plate 355 a, the plug-in unit 50 is blocked outside the subrack 1 and cannot be inserted into the subrack 1 thereafter, which functions as a mis-inserting protection. Once the combination of code pins on the mounting panel 52 matches the corresponding flake 40, the plug-in unit 50 can be completely slid into the subrack 1 and engaged with the connector. Then the handles 56 engage in the corresponding pair of rectangular openings 318 to prevent the plug-in unit 50 from being accidentally withdrawn from the subrack 1. In this state, the gasket 32 resiliently abuts against the alignment pin 54 to form a grounding path between the bottom wall 30 and the plug-in unit 50. Finally, the screw 55 is extended through the corresponding through aperture 356 of the first plate 35 and engaged in the corresponding screw aperture 314 of the second plate 31. The plug-in unit 50 is thus secured in the subrack 1.

To remove the plug-in unit 50 from the subrack 1, the screw 55 is disengaged from the screw aperture 314. The handle 56 is rotated downwardly so that it disengages from the rectangular openings 318. The plug-in unit 50 can then be easily slid out from the subrack 1.

It is understood that the invention may be embodied in other forms without departing from the spirit thereof. Thus, the present example and embodiment are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. 

1. A subrack, comprising: a plurality of plug-in unit, each comprising a printed circuit board and a mounting panel attached to an end of the printed circuit board, each of opposite ends of the mounting panel comprising an alignment pin, and a combination of code pins; a pair of parallel sidewalls; and a bottom wall and a top wall fixed between the side walls to cooperatively define a receiving space therebetween adapted to accommodate the plug-in unit; wherein each of the bottom wall and top wall comprises: a first plate comprising a main portion and a recessed edge portion, the main portion defining a plurality of spaced slide channels for slidably receiving the printed circuit boards therein respectively, and a plurality of alignment holes adjacent corresponding slide channels for receiving the alignment pin to guide the plug-in units into said receiving space, the recessed edge portion forming a plurality of L-shaped flakes corresponding to the combination of code pins in front of each slide channel; and a second plate engaging with the first plate; wherein the height, length and deviation to slide channel of the flakes formed in front of the slide channels varying with different combination of code pins on the mounting panel, in order to match the combination of code pins on the mounting panel and let the plug-in unit be inserted into the subrack for preventing from mis-inserting operation.
 2. The subrack as described in claim 1, wherein the top wall is substantially a mirror image of the bottom wall.
 3. The subrack as described in claim 1, wherein the plug-in units further comprises a screw extending therefrom.
 4. The subrack as described in claim 1, wherein the second plate comprises a vertical portion defining a plurality of screw apertures therein, the screw apertures engagingly receiving the screws of the plug-in unit respectively, at least one horizontal portion extending from a side of the vertical portion, the at least one horizontal portion being attached to the recessed edge portion thereby fixing the first and second plates together.
 5. The subrack as described in claim 1, wherein the recess edge portion of the first plate sequentially comprises first, second and third bent plates integrally joined together at respective perpendicularly bent junctions therebetween, the first bent plate engaging with a horizontal portion of the second plate, the third bent portion engaging with a another horizontal portion of the second plate.
 6. The subrack as described in claim 1, wherein a row of through apertures for receiving the screws on the mounting panels are defined in the second bent plate of the recessed edge portion of the first plate.
 7. The subrack as described in claim 1, further comprising a plurality of gaskets resiliently abutting against the alignment pins to form a grounding path between the bottom wall and the plug-in unit.
 8. The subrack as described in claim 7, wherein a horizontal portion of the second plate extends a plurality of extensions corresponding to the alignment holes of the main portion of the first plate, and the gaskets are mounted between the extensions and the alignment holes, in order that the gaskets can resiliently abutting on the alignment pin after the plug-in unit is assembled.
 9. The subrack as described in claim 7, wherein the gaskets are adhered to the extension.
 10. The subrack as described in claim 7, wherein a horizontal portion of the second plate defines a row of rectangular openings.
 11. The subrack as described in claim 10, wherein the mounting panel further comprises a pair of handles at top and bottom ends of the mounting panel respectively, each handle forms a claw, when the plug-in unit is completely received in the subrack the claws are engaged with the rectangular openings and secured the plug-in unit in the subrack.
 12. A subrack assembly, comprising: a plurality of plug-in units having a combination of closely arranged code pins, each of said code pins essentially positioned at a confined area while selectively located, within said confined area, at one of the more than one positions in an imaginary vertical plane perpendicular to a front-to-back direction; a plurality of receiving sections side by side arranged with one another and extending along said front-to-back direction each for receiving a corresponding plug-in unit; a front portion of each of said receiving sections defining at least a single constraint device which extends in a specific configuration so as to not only comply with at least two corresponding code pins when a correct plug-in unit is received in the receiving section but also block at least one incompliant pin extending from an incorrect plug-in unit for preventing mis-insertion of the incorrect plug-in unit.
 13. The subrack assembly as claimed in claim 12, wherein said constraint extending essentially along a lateral direction perpendicular to said front-to-back direction.
 14. The subrack assembly as claimed in claim 12, wherein said constraint device is stamped out from a metal plate which also defines a plurality of receiving slots for receiving the plug-in units.
 15. The subrack assembly as claimed in claim 12, wherein there are more than one of said one piece constraint devices having different lengths along a lateral direction perpendicular to said front-to-back direction, and different heights along a vertical direction perpendicular to both said front-to-back direction and said lateral direction.
 16. The subrack assembly as claimed in claim 12, wherein there is only one one piece constraint device in each of said plug-in units.
 17. A subrack assembly, comprising: a plurality of plug-in units having a combination of closely arranged code pins, each of said code pins essentially positioned at a confined area while selectively positioned, within said confined area, at one of the more than one positions in an imaginary vertical plane perpendicular to a front-to-back direction; a plurality of receiving sections side by side arranged with one another and extending along the front-to-back direction each for receiving a corresponding plug-in unit; a front portion of each of said receiving sections defining a single constraint device which extends in a specific configuration so as to not only allow at least one corresponding code pin to pass by for proper insertion of a correct plug-in unit into the receiving section but also block at least one incompliant pin extending from an incorrect plug-in unit for preventing mis-insertion of the incorrect plug-in unit; wherein said single constraint device is stamped and formed from a metal plate.
 18. The subrack assembly as claimed in claim 17, wherein said single constraint device extends essentially along a lateral direction perpendicular to both said front-to-back direction and a vertical direction defined by said imaginary vertical plane.
 19. The subrack assembly as claimed in claim 18, wherein said code pins of each of said plug-in units are arranged along said lateral direction, and more than one of said code pins share said single constraint device with others.
 20. The subrack assembly as claimed in claim 17, wherein said single constraint device defines an L-shaped configuration. 